refactor: 简化卡片组件样式布局并移除冗余内边距设置

src/app.css

@@ -337,19 +337,12 @@ body.single-col .post-list {
 
 @media screen and (min-width: 767px) {
 	.card {
-		padding: 20px;
 		border: 2px solid var(--text-color);
 		border-bottom: 2px solid var(--text-color);
 		transition: 0.2s cubic-bezier(0.25, 0.46, 0.45, 0.94) border-color;
 	}
-	.card.has-cover {
-		padding-top: 0;
-		padding-left: 0;
-		padding-right: 0;
-	}
-	.card.has-cover .content-wrap {
-		padding-left: 20px;
-		padding-right: 20px;
+	.card .content-wrap {
+		padding: 20px;
 	}
 	.card-link:hover .card {
 		border-color: var(--accent-color);